How do I use this result?

If PE is 'Unlikely,' clinicians often use a D-dimer test to rule out PE. If 'Likely,' imaging like CTPA is usually the next step.

Wells' Score for PE – Pulmonary Embolism Probability | CalcTools

Estimate the clinical probability of pulmonary embolism to guide diagnostic imaging. Diagnostic safety service.

Pulmonary Embolism (PE) is a diagnostic challenge because its symptoms are often non-specific. Performing expensive and radiation-heavy CT scans on every patient with shortness of breath is neither efficient nor safe. The Wells' Score is the clinical standard for determining 'pre-test probability.' Our Wells' PE service helps doctors categorize patients into 'Likely' or 'Unlikely' groups, ensuring that the right patients get the right tests at the right time.

Clinical signs/symptoms of DVT+3.0 Points

PE is #1 diagnosis or equally likely+3.0 Points

Heart rate > 100 bpm+1.5 Points

Immobilization or surgery in past 4 weeks+1.5 Points

Previous PE or DVT+1.5 Points

Hemoptysis+1.0 Points

Malignancy (treated/palliative in 6mo)+1.0 Points

Wells' Score

0.0points

Low Probability

PE probability is low (approx. 1.3%). Consider using a D-dimer test to rule out PE.

Medical Disclaimer: This tool is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Evidence & References

Wells PS, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: clinical experience with a 7-item model. Ann Intern Med. 2001.

How it Works

The tool applies weighted points to clinical findings (some 1.5, some 3.0 points). It sums these to provide a total score and a corresponding clinical probability category.

Calculation Formula

Sum of weighted clinical factors

Calculation Examples

1. **Likely**: Tachycardia (1.5) + PE most likely (3.0) = **4.5**.

Why use this tool in your daily life?

Safety through probability. This service is a vital part of the diagnostic algorithm, helping to prevent the over-testing of healthy patients while ensuring that life-threatening clots are never missed.